The invention has application to industrial process piping installations which are common to many industries, including the oil and gas, petrochemical and mining industries. A requirement associated with most major projects concerning such installations is that the piping be hydrostatically and/or pneumatically tested, prior to pre-commissioning, so as to ensure conformity with design and operating parameters. Such testing is generally followed by a cleaning phase which may involve subsonic air blasting. Until the installation is commissioned, it is not desirable to expose control elements, such as valves and like elements, to the rigours that will be experienced during assembly of the installation, cleaning of the assembled installation and testing of the installation prior to commissioning. Throughout the specification and claims the term “appliance” shall be taken as referring to control elements, such as valves, gauges, flow restrictors and like elements, which are installed in a fluid line in order to control and/or monitor the fluid flow through fluid line.
For this reason, it is not uncommon for such control elements to be installed and then removed as many as three times over the course of construction, testing and cleaning. This generally involves construction of purpose-built temporary pipe inserts (which may be known in the industry as test pups, jumper spools, temporary spools or test bobbins and which will hereinafter be referred to as “test pups” or a “test pup” as the context requires) to replace each control element. In installations which incorporate tens or hundreds of control elements, this practice is unwieldy and wasteful because, in most instances, a new test pup is created each time and for each control element and, where the installation is to be subjected to testing, each test pup must be fabricated to the same standards as the control element which it is intended to replace. Associated shortcomings in this regard include triple-handling and installation, which compromises the mechanical integrity of the pipe system, as well as the need to subject the test pups to non-destructive testing to ensure their fitness for use during testing and cleaning. This results in unnecessary expense, time delays and safety risks. In addition, there is an increased likelihood of damage to the control elements each time they are installed and then removed.